Automatic stop-motion arrangements for knitting machines and the like



y 3, 1956 R. BUCK ET AL 2,752,768

AUTOMATIC STOP-MOTION ARRANGEMENTS FOR KNITTING MACHINES AND THE LIKE Filed March 31. 1950 l W Z2 AUTOMATEC STOP-MQTIGN ARRANGEMENTS FOR KNITTING MACHINES AND THE LIKE Robert Buck, Carl Wessner, and Hermann Kessler, Rottenburg (Neckar), Germany, assignors to Fouquet- Werk, Franz & Planck, Rottenburg (Necltar), Germany, a limited partnership Application March 31, E561, Serial No. 153,il72 Claims priority, application Germany April 1, 1949 30 Claims. (Cl. 66l66) The present invention relates to automatic stop-motion arrangements for knitting machines, looms and like machines, and more particularly, but not exclusively, for circular knitting machines.

It is known to provide in machines of the character, stop-motion devices or arrangements for the purpose of arresting the machine upon rupture of a thread, or upon occurrence of other defects in the knitted fabric. The arrangements heretofore known usually include thread riders, feelers or detectors, each feeling the tension of a thread respectively assigned to it so that rupture of the thread causes the rider to drop, thereby actuating an electrical cut-out switch or a mechanical tie-coupling device. In another known arrangement of this type a plurality of feelers is in contact with knitted or woven product, each feeler being entrainable by the product upon encountering a gap due to a broken thread or some other defect, to eifectuate electrical or mechanical disconnection by means of a suitable linkage engaged by the feeler.

Some of the drawbacks in all of these known arrangements are lack in simplicity of construction, lack in sensitivity in response, and lack in rapid operation and efficiency. Generally each feeler with its associated linkage occupies considerable space so that only a comparatively small number of detecting stations can be accommodated on the machine. Also, physical requirements dictate that each such detecting station be mounted at some distance from the location where the fabric is formed so that any defects originating at that location will go undetected for a considerable length of time, thereby causing waste of material as well as loss of productive time.

It is, therefore, an object of the invention to provide means enhancing the speed of response of a stop-motion arrangement and affording control and feeling of the fabric close to its location or point of formation.

Another object of this invention is to provide simplied means for detecting small gaps or defects in fabric material, the number of such detecting means being predetermined to allow scanning of the entire width or circumference of the material and being conveniently disposed on the machine of the aforesaid character.

A further object of the present invention is to provide means reducing the number of feeler members required in a stop-motion arrangement to a minimum, to each feeler being imparted a high-sweep movement in transverse direction to the movement of the fabric or like moving product or material to be supervised.

Still another object of the invention is to provide simplified means for mechanically or electrically de-coupling the machine, in particular a knitting machine, by including in a control circuit responding to the operation of the feeler members a return path constituted by one of the elements of the machine itself.

According to a further feature of the invention, each of the feelers engaging the finished product or material constitutes an element of a respectivecontrol circuit and Patented July 3, 1956 is normally separated from a co-operating. contact element by the product to be supervised.

According to another feature of the invention, the cooperating contact element is common to all the control circuits and is constituted by a support for the fabric, forming a necessary and existing part of the machine proper.

According to a further feature of the invention, each feeler member is independently movable with respect ,to all other feelermembers and preferably consists of a flexible and elastic needle mounted on acommonbase. It has been found advantageous to use a needle provided with a hook having at its free end a bend forming the point of contact, the hook terminatingin a re-entrant or double-over extremity which prevents entanglement of the needle with the fabric while allowing the needle normally to slide on the fabric but to penetrategaps of very small size within the fabric for closing an electric circuit controlling the movement of the machine. A transverse oscillatory motion, desirable for the reasons set forth above, may be imparted to a plurality of-resilient needles in a simple manner by pointing the needles upstream, i. e. against the direction of the drawing-off movement of the fabric, at a small acute or predetermined angle with respect to this direction of movement.

According to still another feature of the invention,1a scanning movement transverse to the feeding movement of the fabric and independent of the oscillatory movement referred to, is given to the feeler members. Wherethese members are resilient needles positioned in the manner set forth above, the angle of inclinationwith respect -to the direction of movement is preferably such that the needles extend into the direction of this -transverse movement.

In circular knittingmachines, where the loops of the fabric are inclined toward the axis thereof, such positioning will cause the contact portion of the needle toenter more readily into these-loops for the purpose of detecting any undesirable gap.

The above and other objects and features of the invention will become more fully apparent from the following descriptionof a preferred embodiment, reference being made to the accompanying drawing, in which Fig. 1 shows, in longitudinal section a circular knitting machine (only a part thereof beingillustrated as necessary for an understanding of theinvention) togetherwith electrical connections for a stop-motion arrangement made in accordance with the invention; and

Fig. 2 is a fragmentary top plan view of a feeler needle and adjacentparts of the machine of Fig. 1.

Referring now more particularly to Fig. 1, there is indicated by numeral 1 a part of the frame of a circular knitting machine supporting a stationary needle cylinder 2. Cylinder 2 has suitable peripheral slots 2a serving as guides for the vertically disposed knitting needles 3 which are actuated in the conventional manner by a lock member 4 disposed inside retaining means 'or ring 5 rotating about the cylinder. The warp threads 6 and 7 are supplied to the .knitting needles 3 by means of feeder rings 8 and which are mounted coaxially with the needle cylinder 2 on holders or supports 10 and 11. Supports 10 and 11 together with rings 8 and 9 are rotated in opposite directions from a power source, such as the motor 39, by suitable transmission means (not shown) in the direction of arrows 41, 42. The fabric 12 produced by the knitting needles 3 is drawn off in a downward direction through the needle cylinder 2, and is thereby constrained to lie on andmake contact with themner conical or oblique surface 13 of hollow cylinder 2.

Bearing upon the inner surface of the circular fabric 12 are a set of feeler members in the form of resilient needles 14 whose free ends are in the shape of re-entran't or doubled-over hooks, thereby forming a bend 15 on each needle which constitutes a contact point. Since the tips of the hooked ends are diverted from the fabric, the points of the needles cannot become entangled with the knitted material.

The lower end 16 of each feeler needle 14 is secured to an electric current distributor 17, the latter being suspended by means of bolts 18 from horizontal Supporting rails or arms 19. Supporting arms 19 rest freely on the holder or support of the upper feeder ring 8 from which they are separated by insulating plates or discs 2t Movement is imparted to the distributor ring 17 by means of suitable projections extending upwardly from the holder 10, these projections being, in this instance represented by screws 21 which serve to secure holder 10 to its feeder ring 8. It will be clearly seen in Fig. 1 that screws 21 while not passing through arms 19, are in contact with insulating discs 29, thereby abutting against and operatively entraining the latter as well as arms 19 secured to discs 20.

In Fig. 2, showing part of the distributor ring 17 and one of the needles 14 carried thereby, arrow 41 indicates the direction of rotation of the ring and of its needles. At 40 there is shown an axial plane of the ring 17 which passes through the fixed end 16 of one of the needles 14, the angle or indicating the inclination of the needle 14 with respect to this plane. It will be noted that the free end 15 of the needle leads or is disposed to extend ahead of the fixed end 16 in the direction of rotation of the ring 17. Thus, it can be seen that the longitudinal axis of each needle 14 is disposed along a line which is horizontally and vertically inclined with respect to said axial plane.

Electric current is supplied by way of a conductor 22 to the distributor ring 17 which is insulated from the frame 1 of the machine, the conductor 22 leading to electric current feeding means in the form of a resilient sliding contact arm 43 which, it will be understood, is always in engagement with at least one of the supporting arms 19. The circuit of conductor 22 is completed through a manual circuit breaker or switch 23 parallel solenoid windings 24, 35 and the secondary of transformer 25 to ground at 26, this ground being extended through the frame 1 of the machine to the needle cylinder 2 whose conical part 13 represents the contact element co-operating with the current-carrying feeler needles 14. A source 44 of alternating current is connected across the primary of transformer 25.

Core 28 of solenoid 24 being urged upwardly by a compression spring 27, serves as a latch for a lever 30 which is biased by a tension spring 29. Lever 30 carries a nose or spur which engages a projection or flange 46 on the male or driven part 31 of a conical friction clutch, this part mating with a female or driving part 32 designed as a belt pulley. Part 32 is freely rotatable on the machine shaft 33 but is axially non-displaceable with respect thereto; part 31 being keyed to the shaft 33 as indicated at 34, is axially slidable thereon but upon rotation positively entrains this shaft.

The core of solenoid winding 35 carries two armatures 36, 37 co-operating with respective contact plates; these armatures and contact plates complete in inoperative position of the solenoid 35 an energizing circuit for motor 39 including the source 44 and conductors 38 and 38a.

The operation of the stop-motion arrangement described is as follows:

The knitted product 12 formed by the knitting needles 3, being continuously advanced or drawn off downwardly through the cylinder 2 passes between the stationary support 13 and the bent contact points 15 of the feeler needles 14. Simultaneously with this feeding movement, the current-carrying assembly parts 17, 18, 19 supporting the needles 14 rotate with the holder 1t) and the feeder ring 8 in the direction of arrow 41; thus, there results a helical or spiral, relative scanning movement between 4 the contact points 15 and the fabric 12. Distributor ring 17 defines a horizontal plane upon rotation whereas inclined feeler needles 14 define a conical surface due to their inclination.

The loops of the mesh material or fabric 12, passing beneath the free ends 15 of the feeler needles impart to the latter a succession of impulses (in transverse direction to the needle ends) which cause these needles to vibrate, thereby giving rise to an oscillatory sweep movement perpendicular to the feeding movement of the fabric; this sweep movement is independent of the helical or spiral scanning movement and extends the effective range or amplitude of oscillation of each needle, thus enabling a substantial reduction in the number of needles employed.

The needles 14, by virtue of their particular nonradial mounting, will not encroach upon one another in their vibratory movement, as will be apparent from Fig. 2. where the orbits of their oscillatory sweep have been indicated in dot-dash lines. Since the movement of the fabric relative to the needles will be clockwise, as viewed in Fig. 2, the helical strip of fabric scanned by each needle will be appreciably inc-lined with respect to its oscillatory sweep so that each needle will effectively scan a strip of substantial width. It will be understood that these strips may be made to overlap to a suflicient extent to insure reliable scanning of every portion of the fabric.

As long as all the feeler needles are separated from the grounded fabric support 13 by the fabric12, the solenoids 24 and 35 are de-energized and the machine operates normally. When, however, one or more of these needles make contact with this support by penetrating the fabric 12 through a defective portion thereof, the control circuit hereinabove described is completed (assuming manual switch 23 to be closed) and the solenoid 24 attracts its core 28, thereby unlatching the lever 30 and allowing spring 29 to disengage the coupling part 31 from coupling part 32 and removing driving power from shaft 33. At the same time the solenoid 35 breaks the circuit of motor 39.

It should be noted that the solenoid 24 brings about a trigger action so that a subsequent breaking of this control circuit will be inelfective to re-operate the machine until, usually after inspection and repair, the operator has restored the latch 28 to the normal position, as illustrated. Such breaking of the circuit may, of course, result from the inertia of the system causing the contact point 15 of the feeler needle to move past the defective portion, although suitable means, such as brakes, may be provided to arrest the shaft 33 virtually instantaneously after it has been de-coupled from the pulley 32. It will also be understood that the circuit of motor 39 may be equipped with similar locking means to prevent premature re-energization. Furthermore, although the use of two circuits for disconnecting power from both the motor 39 and the driven shaft 33 has been shown by way of illustration, in practice the provision of only one of these circuits or its equivalent will usually be sufficient.

The loose mounting of the assembly parts 14-19 on the holder 10 of the upper feeder ring 8 has the advantage of enabling this entire feeler assembly to be removed as a unit from the machine, by simply lifting it out of the cylinder 2. Inspection of the defective portion of the fabric and remedy of the defect and its causes may thus be accomplished in a simple and expeditious manner, whereupon the unit may be replaced.

The invention offers the possibility of employing an indefinite number of feeler needles which are individually movable and supported independently from each other on a common current distributor so that the control or stop-motion device can be considerably simplified.

Practically seen, the feeler needles may be distributed over the entire width of the work piece or knitted product and the speed of reaction of or response to the stopmotion device is naturally considerably enhanced due to the multiplicity of feeler needles. In order to most rapidly detect any deficiencies in the fabric or material, it is advantageous that the feeler needles are now located as closely as possible at that part of the machine where the knitted or similar product is formed or produced.

The feeler needles should be so shaped and made from such material that they may perform individual movements transversely to the direction in which the knitted product travels but without normally preventing the smooth drawing-off operation of the latter. Thus, it is possible to reduce the number of the feelers which would otherwise be required for an uninterrupted scanning of the entire area of the product. The feeler needles should be sufiiciently flexible and resilient to such extent that they perform on account of friction with the surface of the product to be supervised transverse oscillations or vibrations with respect to the movement of the product when drawn off. Thus, the feelers are enabled to scan correspondingly broad and extensive strips of material.

If the knitting machine is provided with individual electric drive means, then the feeler needles can be connected to an auxiliary circuit which is closable through relay 35 whose contact pieces 36, 37 control the current supply from said source 44- through conductors 38, 38a to motor 39 of the machine.

It should be understood that the invention is not limited to the specific embodiment shown and described but that it is capable of numerous modifications and adaptations without exceeding its scope as defined in the appended claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent, is:

1. In a machine producing an elongated product for being continuously drawn off and moved; a contact member, a plurality of resilient feeler members normally separated from said contact member by said product, stop-motion means including a control circuit for the actuation of said stop-motion means, said control circuit including said contact member and said feeler members and being completed in response to the engagement of said contact member with at least one of said feeler members, means for imparting a substantially spiral scanning movement to said feeler members relative to said product, said latter means including further means holding said feeler members in a position pointing away from the direction of drawing-01f movement of said product and at an angle with respect to said direction thereby mounting said feeler members for oscillatory motion during said scanning movement.

2. In a machine producing an elongated product continuously drawn off and moved; a contact member forming a support for said product at one surface thereof, a plurality of feeler members disposed at intervals along said product and contiguous to the opposite surface thereof and spaced from said contact member by said product, stop-motion means including a control circuit for actuating said stop-motion means, said control circuit including all of said feeler members in parallel and said contact member and being completed upon any one or more of said feeler members engaging said contact member, and means imparting a substantially spiral scanning movement to said feeler members relative to said product, said latter means including supporting element common to all of said feeler members, each of said feeler members comprising a resilient needle fixed at one end to said supporting element and having its other end pointing against the direction of drawing-off movement of said product.

3. A machine according to claim 2, wherein said other end of each feeler member is provided with a re-entrant hook, said hook forming a bend bearing resiliently upon said product.

4. A machine according to claim 3, wherein each of said feeler members has the longitudinal axis thereof deposed along a line which is horizontally and vertically inclined toward and relative to said product.

5. In a circular knitting machine having a needle cylinder through which moves a fabric in a continuous path; a supporting element centrally extending into said cylinder, a plurality of electrically conductive feeler needles circumferentially spaced around said supporting element and mounted thereon, each of said needles having a free end provided with a contact point, said contact points being disposed contiguous to an electrically conductive portion of said needle cylinder and being normally separated therefrom by said fabric, stop-motion means including a control circuit for actuation of said stop-motion means, said control circuit including all of said feeler needles in parallel and said conductive portion, said control circuit being completed upon any one or more of said feeler needles engaging said conductive portion, and means imparting to said supporting element a rotary movement about the axis of said needle cylinder, thus imparting a substantially spiral scanning movement to said feeler members relative to said fabric said fabric moving in a substantially vertical direction and said needles pointing in the direction opposite to the direction of movement of said fabric in said cylinder.

6. A machine according to claim 5 wherein said conductive portion of said needle cylinder is of downwardly tapering conical shape, said fabric bearing against said portion when moving through said cylinder.

7. A machine according to claim 5, wherein the free ends of said needles further point in the direction of rotation of said supporting element relative to said cylinder.

8. A machine according to claim 5, wherein said supporting element of said feeler needles comprises an elec' trically conductive distributor ring forming part of said control circuit. 7

9. A machine according to claim 5, wherein the axis of said needle cylinder is vertical, and further including rotatable annular feeder means coaxially aligned with said cylinder, said supporting element of said feeler needles being carried by one of said feeder means for rotative entrainment thereby.

10. A machine according to claim 9, wherein said supporting element is provided with radially extending arms resting freely on one of said feeder means, the latter being provided with a projection operatively coupling said feeder means to said supporting element for rotative entrainment of the latter by the former.

11. A knitting machine having knitting needles for making tubular knitted materials, comprising a stationary cylinder for conducting said knitted materials therethrough and provided with means for guiding said knitting needles, retaining means disposed axially of and rotating relative to said stationary cylinder, said retaining means being provided with means for actuating said knitting needles, distributor means disposed axially of and rotating relative to said stationary cylinder, and feeler means mounted for rotation with said distributor means and feeling the surface of said knitted materials substantially at the point of formation thereof, said feeler means including a plurality of resilient needles, each having a longitudinal axis thereof disposed along a line which is inclined with respect to the plane of rotation of said distributor means and which defines a surface of revolution having the shape of a truncated cone, whereby each of said resilient needles sweeps in a spiral path over the surface of said knitted materials along a zigzag line, said feeler means scanning the surface of said knitted materials for detecting defects in the latter.

12. A knitting machine according to claim 11, wherein the longitudinal axis of each of said resilient needles is further disposed along a line which is vertically and horizontally inclined with respect to the plane of rotation of said feeler means.

13. A knitting machine according to claim 12, comprising drive means for rotating said retaining means, and control means operatively connected to said feeler means for interrupting the operation of said drive means upon contact of said feeler means with said stationary cylinder.

14. A knitting machine according to claim 13, said control means including clutch means connected to said retaining means and to said drive means, and trigger means for disengaging said clutch means upon contact of said feeler means With said stationary cylinder.

15. A knitting machine according to claim 13, said control means including a control circuit connected to said drive means for substantially instantaneously interrupting the operation of the latter upon detection of defects in said knitted materials by said feeler means.

16. In a knitting machine for making tubular fabrics; rotatable feelcr means for detecting defects in said tubular fabrics, said feeler means including a plurality of resilient needles each having the longitudinal axis disposed along a line which is inclined with respect to the plane of rotation of said feeler means and defines a surface of revolution having the shape of a truncated cone, whereby each of said needles sweeps over a spiral portion of the surface of said tubular fabrics along a zigzag line, said feeler means scanning the surface of said fabrics for detecting defects in the latter.

17. In a knitting machine according to claim 16, each of said resilient needles having a longitudinal axis further disposed along a line which is both vertically and horizontally inclined with respect to the plane of rotation of said feeler means.

18. In a knitting machine according to claim 16, including control means connected to and actuated in response to operation of said feeler means for controlling the operation of said knitting machine.

19. In a knitting machine according to claim 16, including clutch means for controlling making of said fabrics, a control circuit for operating said clutch means and disengaging the latter from said knitting machine when said feeler means detects defects in said fabrics.

20. A device for interrupting the operation of a knitting machine making tubular knitted material and for detecting defects in the latter; comprising a source of electricity for operating control means, -a control circuit connected thereto, said control circuit comprising a stationary electrically conductive hollow cylinder for conducting said material therethrough, rotatable electrically conductive feeler supporting means concentrically mounted within said cylinder and including a plurality of electrically conductive resilient feeler needles, each having the longitudinal axis thereof disposed along a line which is inclined with respect to the plane of rotation of said feeler supporting means thereby defining a surface of revolution having the shape of a truncated cone, whereby each of said resilient needles sweeps over a spiral portion of the surface of said knitted material along a zigzag line and said feeler means thereby scanning the surface of said knitted material for detecting defects in the latter, said control circuit being shorted when said feeler needles contact said knitted material and being closed when at least one of said feeler needles contacts said hollow cylinder due to a defect existing in the surface of said knitted material to thereby interrupt the operation of said knitting machine.

21. A device according to claim 20, wherein the longitudinal axis of each of said resilient feeler needles is disposed along a line which is both horizontally and vertically inclined with respect to the plane of rotation of said l'feeler supporting means.

22. A device for detecting defects in tubular knitted material; comprising an electrical control circuit connected to an electric current supply source and comprising a stationary electrically conductive hollow cylinder for conducting said material therethrough, rotatable electrically conductive feeler supporting means concentrically mounted within said cylinder and including a plurality of electrically conductive resilient feeler needles, each having the longitudinal axis thereof disposed along a line which is inclined with respect to the plane of rotation of said feeler supporting means thereby defining a surface of revolution having the shape of a truncated cone, whereby each of said resilient needles sweeps over a spiral portion of the surface of said knitted material along a zigzag line, said feeler means scanning the surface of said knitted materials for detecting defects in the latter, said control circuit being shorted when said feeler needles contact the surface of said material and being closed when at least one of said feeler needles contacts said hollow cylinder due to the existence of a defect on the surface of said material to thereby detect the existence of said defect.

23. A device according to claim 22, wherein the longitudinal axis of each said resilient feeler needles is disposed along a line which is both horizontally and vertically inclined with respect to the plane of rotation of said feeler supporting means.

24. A device for controlling the operation of a knitting machine in response to detection of a defect in the knitted material; comprising, in combination, electrically operable means including an electric circuit therefor, drive means for said knitting machine operatively connected to said electrically operable means, whereby said drive means may be operated to stop said machine upon detection of a defect in said material, first means included in said circuit and forming a support along which one surface of said material runs for delivery from said machine, second means connected to said circuit and rotatable relative to said support, said second means being provided with a bearing surface inclined with respect to the rotational axis of said second means, feeler means spaced from each other and disposed along said bearing surface, whereby said feeler means extend in an angle to said support, said feeler means terminating each in an electric contact end adapted to engage with the opposite surface of said material upon detection of a defect in said material, whereby said circuit is closed through establishment of contact between a respective contact end or" said feeler means and said support, said contact ends of said feeler means being so constructed that said ends are capable of oscillatory movements independent from each other during rotation of said second means.

25. A device according to claim 24, wherein the longitudinal axis of each said feeler means is disposed along a line which is both horizontally and vertically inclined with respect to the plane in which said second means rotates.

26. A device according to claim 24, said drive means including clutch means, said electric circuit further comprising first electromagnetic means connected to said clutch means for disengaging the latter when said circuit is closed to thereby interrupt the operation of said knitting machine.

27. A device according to claim 24, said electric circuit further comprising an electric current supply source, and electromagnetic means interposed in the portion of the circuit between said supply source and said drive means for disconnecting the latter from said supply source, when said circuit is closed to thereby interrupt the operation of said knitting machine.

28. In a machine producing an elongated product to be continuously drawn off and moved; a contact member, a feeler member normally separated from said contact member by said product, stop-motion means including a control circuit for the actuation of said stopmotion means, said control circuit including said contact member and said feeler member and being completed in response to the engagement of said contact member with said feeler member, and means for imparting a substantially oblique scanning movement to said feeler member relative to said product, said latter means including support means for said feeler member preventing the latter from following the movement of said product and mounting said feeler member for oscillatory motion during said scanning movement.

29. A device for use in knitting machines to detect any defect in material when delivered from said knitting machine; comprising a substantially cylindrical, hollow support having one surface tapering toward another surface of said support at one end of the latter, knitting needles disposed for reciprocal movement adjacent said one end of said support at said other surface, whereby material coming from said knitting needles is directed by said one end of said support for movement along said one surface of the latter, and feeler means supported remote from and rotatable with respect to said one surface of said support, said feeler means including end contact means inelinedly disposed with respect to and positioned adjacent said one end of said support, whereby said knitting needles and said contact means converge toward each other adjacent said one end of said support, said end contact means of said feeler means being freely carried by the latter, respectively, for performance of oscillatory motion during said rotation to thereby scan said material along a substantially spiral path, when said material upon delivery from said needles moves along said one surface of said support, said material being immediately accessible to said contact means adjacent said one end of said support for detection of defects in said material.

30. A device according to claim 29, including a rotatable distributor ring for supporting said feeler means and positioned remote from said one surface of and for rotation co-axially to said cylindrical support, first electric conductor means establishing electrical connection from a source of electric current through said distributor ring to said contact means, second electric conductor means establishing electrical connection from said source of electric current to said support, whereby a control circuit is operable by said contact means and said support upon detection of defects in said material, and means influencing operation of said knitting machine upon closing of said control circuit by any of said contact means with said support.

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